What is the derivative of log(sin^2(x))?

1 Answer
Aug 31, 2015

If you don't remember the derivative of log_10(u), you can derive it like so:

y = log(sin^2x)
10^y = sin^2x

d/(dx)[10^y] = 10^yln10((dy)/(dx))

(It is an extension of d/(dx)[a^x] = a^xlna.)

Therefore, you get:

10^yln10((dy)/(dx)) = 2sinxcosx

color(blue)((dy)/(dx)) = (2sinxcosx)/(10^yln10)

= (2sinxcosx)/(sin^2x*ln10)

color(blue)(= (2cotx)/(ln10))